1. Field of the Invention
The invention relates in general to an apparatus for ultrasonic measurements of liquid flow.
2. State of the Art
Ultrasonic devices are known for measuring flow in small pipelines having inside diameters less than 12 cm. Such devices generally measure flow velocity and from velocity derive flow. U.S. Pat. No. 3,817,098 to Brown discloses a number of configurations for such devices.
The Brown configurations illustrate a number of disadvantages heretofore of such devices. In one configuration transducers are positioned at a spaced interval along a pipeline. To so position the transducers requires a length of straight pipeline longer than the spaced interval. Further, the size and shape of these transducers are important as the transducers form obstructions to flow in the pipeline. In another configuration transducers are individually positioned in a side arm set back from a flowpath. As so positioned, these transducers are not obstructive to flow but flow in the arms is static which can allow bubbles or deposits to collect on the transducers and interfere with transmission of signals by the transducers.